Bioluminescence is a localized phenomenon caused when organisms are stimulated by flow agitation. As a result of this effect, submerged moving objects will be highlighted with a blue-green glow and often can produce spectacular glowing wakes from ships and submerged craft. This effect is so widespread in the world's coastal regions that some level of bioluminescence is almost always present. Dinoflagellates, ubiquitous unicellular plankton also known for producing harmful blooms, are the most common sources of bioluminescence in the littoral zone. Dinoflagellates often exist in sufficient density such that ships, swimmers and submersibles can readily be detected by airborne, seaborne, or land-based observers. The intensity of bioluminescence is dependent on the local abundance of the dinoflagellates, which varies both in space and time. This makes the phenomenon difficult to predict, and when bioluminescent organisms are present, it is unavoidable by any practical means.
Ships, submarines and swimmers can readily be detected in the dark when strong bioluminescence activity exists, which poses a serious problem when movements need to be hidden from detection. When bioluminescence is present, there are ways to minimize the amount of signature that is detectable from the surface. In the case of submersibles and swimmers, detection vulnerability can be reduced by either decreasing the amount of flow stimulation caused by the craft (e.g., reducing speed) or by increasing operating depth, thus attenuating the surface signature caused by bioluminescence. The problem is that the operator must know in real time the bioluminescence intensity generated by the submersible's movement and how this is translated to surface signature and ultimately the vulnerability to detection. The operator must also know to what extent tactical maneuvers are effective in changing the bioluminescence signature at the surface.
Currently, this real-time self-monitoring capability does not exist.
Needs exist for a real-time, self-monitoring bioluminescence signature determination sensor.